From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57560C33CA9 for ; Mon, 13 Jan 2020 22:38:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1853620CC7 for ; Mon, 13 Jan 2020 22:38:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="E43zTo2/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1853620CC7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AE20C8E0005; Mon, 13 Jan 2020 17:38:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A93738E0003; Mon, 13 Jan 2020 17:38:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A96A8E0005; Mon, 13 Jan 2020 17:38:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0081.hostedemail.com [216.40.44.81]) by kanga.kvack.org (Postfix) with ESMTP id 8310E8E0003 for ; Mon, 13 Jan 2020 17:38:22 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 3DF0D8248D7C for ; Mon, 13 Jan 2020 22:38:22 +0000 (UTC) X-FDA: 76374076044.16.shop61_ed4d39ea9c04 X-HE-Tag: shop61_ed4d39ea9c04 X-Filterd-Recvd-Size: 2242 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Mon, 13 Jan 2020 22:38:21 +0000 (UTC) Received: from akpm3.svl.corp.google.com (unknown [104.133.8.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DDF24206DA; Mon, 13 Jan 2020 22:38:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578955101; bh=c+Fd7/nkhkjHE15QEFRCHC7FLzwt5umlhKtyMd7aYZE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=E43zTo2/uPl7YCbkcpUSlc9rW1naLsqFv9CuQ4pqH8/9eJEJe7E1hX7bjBagXlNf7 aqQ2aXXuHquRo0r+KHgt8x2sUqBXP/gtB+VfL+NIxsqvO5Sbllk48OJfys/42XGTIL BYids4SShjxMzZ54wFsng3yvqVic6ApqR4qRFibU= Date: Mon, 13 Jan 2020 14:38:20 -0800 From: Andrew Morton To: Li Xinhai Cc: linux-mm@kvack.org, "Kirill A. Shutemov" , Mike Kravetz , Michal Hocko Subject: Re: [PATCH v4] mm/page_vma_mapped.c: Explicitly compare pfn for normal, hugetlbfs and THP page Message-Id: <20200113143820.3707ae928234e7abe64350a8@linux-foundation.org> In-Reply-To: <1578737885-8890-1-git-send-email-lixinhai.lxh@gmail.com> References: <1578737885-8890-1-git-send-email-lixinhai.lxh@gmail.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, 11 Jan 2020 10:18:05 +0000 Li Xinhai wrote: > When check_pte, pfn of normal, hugetlbfs and THP page need be compared. > The current implementation apply comparison as > - normal 4K page: page_pfn <= pfn < page_pfn + 1 > - hugetlbfs page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR > - THP page: page_pfn <= pfn < page_pfn + HPAGE_PMD_NR > in pfn_in_hpage. For hugetlbfs page, it should be > page_pfn == pfn Does this have any runtime effects? > Now, change pfn_in_hpage to pfn_is_match to highlight that comparison > is not only for THP and explicitly compare for these cases.